835076 Mercruiser OVERHAUL KIT

Illustration 1 g00813445
Typical schematicTest Step 1. Check for Connector Damage.
Turn the keyswitch to the OFF position.
Disconnect the main power.
Thoroughly inspect the ECM connectors J1/P1 and J2/P2. Inspect all of the other connectors. Refer to Troubleshooting, "Inspecting Electrical Connectors" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.
Check the ECM connector (allen head screw) for the proper torque of 6.0 N m (55 lb in).
Check the customer connector (allen head screw) for the proper torque of 2.25 0.25 N m (20 2 lb in).
Check the harness and the wiring for abrasion and pinch points.Expected Result:The connectors and wiring should be free of the following problems: damage, corrosion, abrasion and incorrect attachment.Results:
OK - The connectors and wiring are okay. Proceed to test step 2.
Not OK - The connectors and/or wiring need repair.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Stop.Test Step 2. Check the Battery Voltage.
Turn the circuit breaker for the battery to the OFF position.
Turn the keyswitch to the OFF position.
Measure no-load battery voltage at the battery terminals. Refer to Testing and Adjusting, "Test Tools for the Electrical System" for the proper procedures to check the batteries.
Load test the batteries. Use the 4C-4911 Battery Load Tester. Refer to the Operating Manual, SEHS9249. Refer to Special Instruction, SEHS7633.Expected Result:The no-load voltage at the batteries should be at least 23.5 VDC and the batteries should pass the load test.Results:
OK - The battery voltage is okay and the battery passes the load test. Proceed to test step 3.
Not OK - The battery voltage is incorrect and/or the battery fails the load test.Repair: The batteries or the alternator are causing the problem. Recharge the batteries or replace the batteries. Verify that the original condition is resolved. Refer to Testing and Adjusting, "Electrical System". Stop.Test Step 3. Check the Voltage to the ECM.
Remove ECM connector P1.
Measure the voltage between P1-4 and P1-11.
Measure the voltage between P1-6 and P1-5.Expected Result:The voltage should be 1 VDC from the voltage at the battery terminals.Results:
OK - The voltage is 1 VDC from the voltage at the battery terminals. The voltage at the ECM is okay. Proceed to test step 4.
Not OK - The voltage is not 1 VDC from the voltage at the battery terminals. The voltage is not correct at the ECM.Repair: There is an open circuit or excessive resistance in the wiring or connections between the batteries and the ECM. There is an open circuit or excessive resistance in the wiring or connections between engine ground and the ECM. Repair the connectors or wiring and/or replace the connectors or wiring. Stop.Test Step 4. Check the Voltage to the ECM Input for the Keyswitch.
Install a Breakout T at ECM connector J1/P1.
Turn the keyswitch to the ON position.
Measure the voltage between P1-23 and P1-11.
Turn the keyswitch to the OFF position.
Remove the Breakout T and reconnect all wires and connectors.Expected Result:The voltage should be 24 3 VDC.Results:
OK - The voltage is 24 3 VDC. Proceed to test step 5.
Not OK - The voltage is not 24 3 VDC. Proceed to test step 7.Test Step 5. Check the Analog Sensor Power Supply.
Install a Breakout T at ECM connector J1/P1.
Remove the wires from P1-36 and P1-30 at ECM connector J1/P1.
Turn the keyswitch to the ON position.
Measure the voltage between P1-36 and P1-30 on the Breakout T.
Turn the keyswitch to the OFF position.
Remove the Breakout T and reconnect all wires and connectors.Expected Result:The voltage should be 5.0 0.2 VDC.Results:
OK - The voltage is 5.0 0.2 VDC. Proceed to test step 6.
Not OK - The voltage is not 5.0 0.2 VDC.Repair: Replace the ECM. Stop.Test Step 6. Check the Digital Sensor Power Supply.
Install a Breakout T at ECM connector J1/P1.
Remove the wires from P1-35 and P1-29 at ECM connector J1/P1.
Turn the keyswitch to the ON position.
Measure the voltage between P1-35 and P1-29 on the Breakout T.
Turn the keyswitch to the OFF position.
Remove the Breakout T and reconnect all wires and connectors.Expected Result:The voltage should be 8.0 0.4 VDC.Results:
OK - The voltage is 8.0 0.4 VDC.Repair: The power to the ECM is correct. The ECM power supplies are operating correctly. There may be an intermittent problem. Check connectors and wiring for problems. Stop.
Not OK - The voltage is not 8.0 0.4 VDC.Repair: Replace the ECM. Stop.Test Step 7. Check the Voltage at the Main Power Relay.
Turn the keyswitch to the ON position.
Check the voltage between wire 112-PU on the main power relay and engine ground.Expected Result:The voltage should be 24 3 VDC.Results:
OK - The voltage is 24 3 VDC.Repair: Check that fuse F11 is not open. Check the wires 112-PU and 113-OR between the main power relay and the ECM for an open or short. Make any repairs needed. Stop.
Not OK - The voltage is not 24 3 VDC. Proceed to test step 8.Test Step 8. Check the Voltage from the Keyswitch.
Turn the keyswitch to the ON position.
Measure the voltage from terminal R on the keyswitch to engine ground.Expected Result:The voltage should be 24 3 VDC.Results:
OK - The voltage is 24 3 VDC.Repair: Check the wire 112-PU between the keyswitch and the main power relay for an open or short. Check the wire 200-BK between the main power relay and the engine ground for an open. If these wires are okay replace the main power relay. Stop.
Not OK - The voltage is not 24 3 VDC.Repair: If battery voltage is present on terminal B of the keyswitch, replace the keyswitch. If battery voltage is not present on terminal B of the keyswitch, check the breaker for the keyswitch for an open condition. Repair the wire between the keyswitch and the battery. Stop.